Trichlorosilane (SiHCl3), which is used as a raw material for the production of highly pure silicon (Si), can be produced by conversion through a reaction of silicon tetrachloride (SiCi4: tetrachlorosilane) with hydrogen.
In other words, silicon is produced by the reductive reaction and the thermolysis reaction of trichlorosilane represented by reaction schemes (1) and (2) shown below, and trichlorosilane is produced by the conversion reaction represented by reaction scheme (3) shown below.SiHCl3+H2→Si+3HCl  (1)4SiHCl3→Si+3SiCl4+2H2  (2)SiCl4+H2→SiHCl3+HCl  (3)
As an apparatus for producing this trichlorosilane, for example, Patent Document 1 (Japanese Patent No. 3,781,439) proposes a reactor in which a reaction chamber surrounded by a heating element is of a dual chamber design having an outer chamber and an inner chamber formed by two concentrically positioned pipes, a supply gas of hydrogen and silicon tetrachloride is supplied to the reaction chamber from below via a heat exchanger disposed in the bottom of this reaction chamber, and a reaction product gas is discharged from the reaction chamber in a downward direction. In the heat exchanger in this reactor, the supply gas supplied to the reaction chamber is preheated by heat transferred from the reaction product gas discharged from the reaction chamber and the reaction product gas is cooled.